xbox. I have a PS3 and the ps3 network isn't as good imo. Plus non of my friends have ps3s so it would be lame to have no friends on a free network, when I can just pay for the service and play with all my friends. Also the party system on the xbox is beast.
EDIT: Also, wrong area, this shouldn't be in BF3 section since we aren't talking about BF3
I have always been an xbox user... So im quite biast but I can say in confidance they both have ups and downs.. HOWEVER I have noticed that PS3's seem to use more power than xbox's so that was a main reason I use xbox to this date...
But all the same I respect PS3 just the same!